Internal combustion engine



y 1933- L. M. WOOLSON 1,918,076

V INTERNAL COMBUSTION ENGINE Filed July 21. 1930 2 Sheets-Sheet 1 5113.4Qwuemtom LI'UNEL M. NDULS'DN. 05: 5:0

5r HIS zxetu rmx EMMA E Nuns-cw July 11, 1933. M, WOQLSQN 1,918,076

INTERNAL COMBUSTION ENGINE Filed July 21, 1930 2 Sheets-Sheet 2 I Igwuanl'oz 51:75. E

Iz/JNEL MNJYULSUN, DECEASED 5r H15 sxscumzx EMMA f. Nauasazv PatentedJuly 11,1933

UNITED STATES eisure PATENT OFFICE LIONEL M. WOOLSON, DECEASED, LATE OFDETROIT, MICHIGAN, BY EMMA F. WOOLSON, EXECUTRIX, 0F BLOOMFIELD VILLAGE,MICHIGAN, ASSIGNOR TOPACKARD'MOTOR CAR COMPANY, OF DETROIT, MICHIGAN, ACORPORATION OF MICHIGAN INTERNAL COMBUSTION ENGINE Application filedJuly 21,

which fuel is forced by a pump actuated in its injection strokes by therelease of a spring which is first compressed by a cam,

such injection being known as the loaded n, v spiing .type. When the camis moving slowly, the action is sufficiently fast to cause the plungeractuating mechanism to closely follow the perimeter of the cam, howeverwhen the cam is speeded up, as it is when the engine is operating undernormal load, the influence of the spring upon the plunger actuatingmechanism is not as fast as the movement of the cam and, consequently,there is a delay in the forcing of the plunger actuating mechanism intocontact with the base circle of the cam, and

consequently the timing of the fuel injection is delayed. Such delay inthe timing of the fuel injection is undesirable and lessens theefficiency of the engine as well as limiting the time for the liquidfuel to mix 'with the compressed air before the piston.

reaches its top position in the cylinder during the compression strokes.

An object of the invention is to providefuel injecting mechanism, of thecharacter described above, which will closely follow the periphery of acam during all speeds at which it may be operated.

Another object of the-invention is to pro- 'vide a multi-cylinderengine, of the radial type, with individual fuel injection mechanism foreach cylinder which are operated bx a single cam rotated from the enginein a manner such that there will be no delay in the time of theinjections, relative to the relation of the cam with the actuatingmechanism.

Another object of the invention is to provide a radial engine withseparat fuel injecting devices for each cylindernwhich are actuated by asingle cam in a manner to 1930. Serial No. 469,326.

provide a uniform timing for the fuel injections regardless of speed andwith which a single adjusting member is associated for simultaneouslyvarying the quantity of fuel contained in the injected charges.

These and other objectsof the invention will appear from the followingdescription taken in connection with the drawings, which form a part ofthis specification, and in which Fig. 1 is a rear elevational View of aradial type of internal combustion engine incorporating the invention,portions of the engine being broken away and in section to illustratethe fuel actuating mechanism;

Fig. 2 is a sectional view taken on line 2-2 of Fig. 1;

'Fig. 3 is a sectional View of the nozzle portion of one of theinjection devices associated with a fragment of one of the cylinders;

Fig. 4 is a fragmentary sectional view peripheral wall of the crank caseand are secured in position by compression bands, one of which isindicated by the numeral 18. Each of the cylinders is formed with a dome19 upon which is secured a head 20, the spaces between the domes 19 andthe pistons 21 within the cylinders providing the combustion chambers inwhich the fuel mixture is intermingled and ignited through the heatresultingfrom piston compression. A single Venturi passage 22 extendsthrough each of the associated heads and domes and provides an air inletand an exhaust outlet, such passage being controlled by a valve 23 whichis normally closed by the springs 24 and 1 opened by conventionalmechanical means including a push rod 25 extending into the compartment16 within the crank case. It will be understood that the engineillustrated 5 is of the four-stroke cycle ty e in which the air chargesare drawn direct y into the cylinders during the suction strokes ofthe-pistons and during the com ression thereof and into which, airlessliqui fuel charges under a high pressure and in an atomized condimountedupon the rear end 28 of the crank shaft is a cam 29 which is driven,preferably from the crank shaft, and at a reduced speed relativethereto. A retainer 30 is screwed upon the crank shaft tosecure the camin a desired position axially, and a bearing 31 is interposed betweenthe crank.

shaft and the cam. In order to drive a cam ata reduced speed from thecrank shaft, a gear 32 is splined to the rear end portion of the crankshaft and meshes with a gear 33 which is carried by a shaft 34 supportedby the rear cover wall of the crank case. Agear 35 is also mounted uponthe shaft 34 and meshes with an internal gear 36 formed onthe inside ofthe periphery 37 of the cam. A starting jaw 38 is fixed to the extremerear end of the crank shaft. The reduction driving mechanism can beprovided with a non-reversing clutch mechanism, as shown in theco-gending' application Serial No. 419,547, led J anuary' 9, 1930, inorder to prevent any kick-back or reversal in starting the engine.

A fuel injecting device, consisting generally of a nozzle portion 39 anda fpump portion 40, is associated with each 0 the cylinders. Each nozzleincludes a barrel 41 having a removable end 42 projecting through thewall of the cylinder, the nozzle being rigidly secured to the cylinderby suitable fastening means 43 in the form of studs or bolts. Extendingin an axial direction within the chamber 16 in the nozzle-barrel is avalve 44 having a head 45 arranged within the conical end of the-axialpassage formed in the section 42 of the nozzle. In order to prevent thehead 45 from touching the wall of the nozzle, a member 46 is screwedupon the outer end of the valve stem for engagement with a stop member47, which can be suitablyadjusted for this purpose. A coil spring 48surrounds the valve stem, within the chamber in the nozzle, and exerts apressure against the member 46 normally tending to maintain the valvehead in its nearest closing position.

The pump casing 49 is screwed upon a depending neck 50 of the nozzle anda. passage 51 establishes communication between the interior-of the pumpcasing and the chamber extending through the nozzle and opening into thecylinder, this arrangement of the neck 50 and the casing 49 clamps thepump barrel 52 in position. prevent return of oil or the passage of airfrom the nozzle chamber into the passage 53 in the pump barrel, there isprovided a one-Way check Valve 54 which is normally seated by a suitablespring. A pump plunger 55 is arranged to reciprocate within the pumpbarrel, and a spring 56 engages the plunger head 57 and is associated ina mannet to normally cause movement of the plunger in a direction awayfrom the nozzle. A fuel manifold extending around the cylinder iscomposed of a plurality of conduit sections 58 which are associated withunions- 59 secured around each of the pump casings by a nut 60.Transverse passages 61 extend through the pum casings and barrels toestablish communication between the manifold unions and the barrelpassages 53, there being a reservoir and a low pressure pump (not shown)for moving liquid fuel oil through the manifold and into the cylinderswhen the plungers 55 are in a relation uncovering the ports 61.

In order to,

With the type of fuel injection devicede- I scribed, the plungers aremoved to a position uncovering the ports 61 by means of the springs .56,and when in such relation, liquid fuel will be moved from the manifoldto completely fill the passage above the plunger. As the plungers aremoved in their injection strokes, they serve to close the ports 61, thuscutting off the fuel supply, and the length of their strokes beyond thepoint where they close the orts 61 will determine the quantity of fuel 0arges forced from the nozzles into the combustion chambers.

In order to regulate the length of the plunger strokes beyond the ports61 to vary the fuel charge quantity, there is provided a ring 62 whichis carried by the wall 14. A rack 63 is secured to the ring andco-operating with the rack is a gear segment 64 which is rotated bymeans of af'shaft 65 to which is fixed a lever 66 adapted to be actuatedby suitable mechanism extending to a point for convenient manualoperation. The plungers each have associated therewith a push rod formedof two sections 67 and 68, the sections 68 being connected to the ring62 by links 63 so thatupon rotation of the ring the angular position ofthe sections 68 will be varied and thereby vary the effective injectionstroke of the plungers.

A slipper 69 is associated with each of the push rod sections 68 and ismounted to rock upon a shaft 70 which extends across the compartment 16and is supported by suitable aligned bearings 71 formed in the partitionwall 14 and the end cover wall 12. The end of the slippers with whichthe push rod sec;

remove .crank shaft is turning in a clockwise direction and the cam isbeing driven therefrom at one-eighth the speed and in an anti-clockwisedirection. With this reduced speed of operation, difiiculty isencountered when the engine is idling in providing a sufficiently fastmotion to the pump plungers to create a high enough pressure to causethe fuel charges to be injected into the compressed air charges in thecylinders a sufficient distance to result in an inter-mingling such thatcompression thereof will cause combustion. The Venturi ports 22 arearranged'tangentially of the cylinders so that air drawn therein isrotating while it is being com pressedand it is requisite that the fuelcharges be atomized to a certain extent and penetrate substantially tothe axis of the rotating compressed air in order that the fuel may bedistributed to form a homogeneous mixture in a very short space oftime,-the fuel charges being injected preferably in a range extendingbetween forty and twenty degrees of the crank shaft angle before thepistons reach the top of their compression strokes. With the fuelinjecting mechanism so far described, actuation of the slipper heels 73by the forward end of the lobes 74 will not impart a fast enough stroketo the plungers to produce'the neces sary pressure behind the fuelcharges when the engine is running at idling speeds or therebelow, suchas it may when being cranked. I

In order to increase the s eed imparted to the plungers upon their inection strokes, when the engine is rotating in its lower speed range,there is provided mechanism associated with the slipper and the cam,which-will now be described. A rod 7 5 extends radially of the crankcase and in substantially a parallel relation with each of the push rodsand is pivotally associated with the end of the slipper opposite fromthe plunger push rod. This rod has a spring retainer 76 associatedtherewith and a coil spring 77 surrounds the rod and bears against theretainer at one end and against a plate 78 at the other end, such plateextending into an aperture in the crank case and being enclosed by acover 79. Suitable bolts or studs 80 are provided to secure the coversand the plates to the crank case. A spring washer 81 is arrangedintermediate the plate and cover and the head 82 of the rods 75 pro ectsthrouh such washer. The washers 81 are normaly bowed and serve thefunction of resisting nfovement of the rods in-,

wardly of the crank case. The slippers are provided with a toe portion83 for engagement with the periphery of the cam while therear end 84 ofthe lobes 74 is formed to permit the toes 83 of the slippers to'substantially immediately be pressed against the base circle of thecam'when the lobes pass beneath the slipper toes. In other words, therear faces 8% pf the lobes are very 1 abrupt.

' The cam is also provided with a plurality of lobes arranged in a planeon the periphery 37 at the rear of the lobes 74 for actuating slippers85 with which the valve push rods 25 are associated. The slippers 85 aremounted upon the shafts 70 adjacent the slippers 69 and the lobes arearranged so that the valves 23 will be opened during the exhaust andsuction strokes of the pistons.

When the engine is running in its lower speed range, the springs 77press the toes 83 of the slippers against the periphery of the cam sothat when the toes ride upon the lobes of the cam, the spring 77 will becompressed, and the plungers 55 will be' moved into a positionuncovering the ports 61. Thus, when the lobes 74 pass from beneath thetoes 83 of the slippers the builtup spring energy will cause a fastmovement of the toes and of the siippers toward the base circle of thecam and such movement will impart an injection stroke to the fuelplunger push rods and the plungers. In this manner, when the cam isturning slowly, a much faster movement of the plungers will result thanif they were actuated by the contact of the heels '73 with the camlobes, and consequently, a much higher pressure is exerted upon the fuelto inject charges thereof into the compressed air in the cylinders.

It is found, however, that with such fuel injecting mechanism when theengine is running in its higher speed range, the cam moves aster thanthe unloading reaction of spring end, and, consequently, the cam movesseveral degrees in its rotation before the toes 83 are moved toward thebase circle by the springs 77. This delays the time at which the. fuelcharges are injected into the cylinders, and such a condition isundesirable because of the short space of time in which the fuel must beintermingled with the compressed air in order to provide a desirable andefiicient operation of the engine. In order to overcome this undesirablecondition, the length of the lobes 74 and the distance between the heeland toe of the slippers is arranged so that during a fast cam rotation,

- the forward end of the lobewill strike the under. In other words, thelag of the springs 77 in functioning, as it effects the slippers,

- when the cam is moving fast has been compensated for by constructingand associating the lobe and the slipper so that injection strokes willbe caused by another means of contact which is accurate and re ular inits action regardless of the cam spce With this arrangement, the lengthof the lobes 7 4 must be only slightly shorter than the distance betweenthe heel and toe of the slip rs. It will thus be seen that when theengine is running in its slower speed range the releasing of the springs77 causes fast fuel injection strokes of the plungers, while a contactbetween the forward end of the cam and the heels of the slippers willcause a fuel injection stroke when the cam is run-' ning in its higherspeed range. With this form of plunger actuating mechanism, the timingof the fuel injection will remain substantially constant regardless ofthe speed of the engine and an efiicient engine operation will result.

Pressure behind the injected fuel is maintained suflicient to insure theproper intermingling of the fuel with the air.in the properly atomizedcondition so that in this manner stalling of the engine, when running atslow speeds, and delayed timing, when running at high speeds, aresubstantially eliminated.

While there is herein described in some detail a specific embodiment ofthe invention, which is deemed to be new and advantageous and may bespecifically claimed,'it is not to be understood that the invention islimited to the exact details of the construction, as it will be apparentthat changes may be made therein without departing from the spirit orscope ofthe invention.

What isclaimed is:

1. In a fuel injection mechanism for internal combustion engines, a pumpplunger,

plunger operating mechanism, a spring for actuating the mechanism tocause plunger injection strokes, another spring for retracting theplunger mechanism between injection strokes, and an engine rotated camfor compressing and suddenly releasing the actuating spring to cause aneffective stroke of the plunger below 'a predetermined engine speed,said cam co-operating-directly with the plunger operating mechanismabove a predetermined engine speed to cause the plunger injectionstroke.

2. In a fuel injection mechanism for internal combustion engines, a pumpbarrel having fuel inlets therein and an. outlet spaced from the inlets,a plunger reciprocable in the barrel and controlling the inlet ports,plunger operating mechanism, a spring for actuating the mechanism tocausethe plunger to close the inlets and force fuel through the outlet,another springfor-retracting the plunger sufliciently to uncover thefuel inlets in the barrel between injection strokes, and an en inedriven cam for compressing and sud enly releasing the actuating springto cause effective plunger strokes below a predetermined engine speed,said cam coacting directly with said operating mechanism to causeeifective plunger strokes above the predetermined engine speed.

3. In a fuel injection mechanism for internal combustionengines, a pumpplunger, operating. connections for the plunger including a rock lever,a spring pressed member engaging one end of the rock lever, a spring forcausing retraction of the plunger between injection strokes, a springpressed member exerting pressure againstthe rock lever in a direction tocause an injection stroke of the plunger and exerting greater pressurethan the retraction spring, and an engine driven cam for actuating therock lever to build up energy behind the member and then suddenlyrelease the same to cause an effective stroke of the'plunger below a'predetermined engine speed, said cam coacting directly with the rocklever above the predetermined engine speed to cause the effectiveinjection strokes of the plungers.

4. In a multi-cylinder internal combustion engine, fuel injectiondevices each including a plunger, individual means retracting theplungers between injection strokes, mechanism including circularlydisposed rock levers associated one with each plunger, reciprocablemembers under spring and cause plunger actuation of the associatedmechanism, and a cam for moving the rock levers to store energy behindthe recipr'ocable members and then suddenly release the same, said camdirectly actuating the rock levers to cause plunger injection strokeswhenthe engine is running above a predetermined speed.

5. In .an internal combustion engine, mechanism for injecting atomizedliquid fuel under high .pressure into air in the combustion chambercomprising a nozzle unit, a pump casing communicating with the nozzleunit, a reciprocable plunger adapted to trap liquid fuel in the casingand to eject the trapped liquid fuel from the nozzle, a rock lever, apush rod structure intermediate the plunger and one end of the rocklever, a rod bearing against the other end of the rock lever, an enginerotated cam having lobes projectin from its base circle, said rock leverbearing against the periphery of the cam, a spring associated with theplung er exerting pressure against the push rod 105 tension associatedto actuate the rock levers eflective actuation of the plunger.

6. In a fuel injection mechanism for internal combustion engines, a pumpbarrel having an inlet and an outlet, a nozzle. communicating with thebarrel outlet, a plunger reciprocable in the barrel, said plungercontrollin the inlet port, a cam having lobes extending from a basecircle, engine driven means for rotating the cam, a rock lever pivotedintermediate its ends adjacent the cam,

an extension at each end of the rock leverprojecting in a directiontoward the cam,

a rod structure intermediate one end of the rock lever and the plunger,a rod bearing against the other end of the rock lever, a spring exertingpressure against the rod structure in a direction toward the rock lever,another spring exerting pressure against the rod in a direction towardthe rock lever, said rod spring exerting greater pressure than the otherspring, rotation of the cam causing the lobes to tip the rock lever in adirection compressing the rod spring and then suddenly releasing thesame, the length of the cam lobes being slightly less than the distancebetween the rock lever extensions to cause engagement of the lobes withone of the extensions prior to the return of the other extension tothescam base circle upon release of the rod spring, when the cam isrotating above a predetermined speed.

7. In a fuel injection mechanism for internal combustion engines, anengine casing, a pump barrel having a fuel inlet and an outlet, aplunger reciprocable in the barrel and controlling the inlet, a nozzle"arranged in communication with the barrel outlet, an engine driven camrotatable within the casing, a rock lever pivoted intermediate its endswithin the casing and ma position to be engaged by the lobes of the cam,said rock lever having a toe-extension adapted to ride upon theperiphery of the cam, a rod engaging the rock lever, said rod beingpiloted within the casing, a coil spring encircling the rod andassociated therewith and with the casing to exert pressure againsttherock lever in a direction toward the cam, a rod structure intermediatethe plunger and the heel end of the rock lever, and spring means forholding the rod structure against the rock lever.

8. In a fuel injection mechanism for internal combustion gngines, a pumpbarrel having fuel inlets therein and an outlet, a nozzle communicatingwith the outlet of the barrel, a plunger reciprocable. in the barrel andcontrolling the inlets, a rock lever, a rod structure intermediate oneend of therock lever and vthe plunger, spring means for maintaining therod structure in contact with the rock lever, a rod engaging the otherend of the rock lever, a cam cooperating with the rock lever, springmeans urging the rod against the rock lever to cause the adjacent endthereof to rideupon the periphery of the cam, said ca'm having lobesformed to raise and suddenly release the end of the rock lever withwhich the rod is associated, and sh'oclg'absorbing means associated withthe rod adapted to become operative whenthe rod is released from the camlobe.

9. In a fuel injection mechanism for internal combustion engines, a pumpbarrel having a fuel inlet and a fuel outlet port, a plungerreciprocable in the barrel and controlling the inlet port, a nozzleassociated with the outlet port, an engine casing, an engine driven cammounted within the casing, a rock lever within the casing" and pivotedthereto intermediate its ends,

a rod structure intermediate the plunger and one end of the rock lever,a rod extending through the casing and bearing against the other end ofthe rock lever, said rod having a head portion exterior of the casing,

shock absorbing means intermediate the casv ing and the head of the rodeffective upon the movement of .the rod inwardly of the 'casing, aspring forpressingthe rod structure. against the rock lever and a coilspring for pressing the rod against the rock lever, said coil springexerting a greater force than the rod structure spring to cause theadjacent end of the rock lever to ride upon the periphery of the cam,said cam being formed with lobes causing movement of the rock lever in adirection to compress the coil spring and'suddenly release the same.

10. In a fuel injection mechanism for internal combustion engines, apump plunger, an engine driven member, plunger operating means includinga rock lever d1- rectly actuated by the driven member above apredetermined engine speed, and releasable compression meansco-operating dlrectly with the plunger operating means and impartingsudden operative movement thereto below a predetermined engine speed.

11. In a fuel injection mechanism for internal combustion engines, apump plunger, plunger operating means including a pivoted member, anengine driven cam engaging the pivoted member to actuate the plungerwhen the engine. is running above a predetermined speed, andreleasablecompression means co-operating with the pivoted member tosuddenly actuate the plunger abutment at each end, an engine driven camengaging the rock lever, and spring pressed means engaging one end ofthe rock lever, said cam operating in a direction so that the lobes willfirst engage the end of the cam with which the spring pressed meansco-operates to store up energy therein which is released beforeengagement by the lobes of the other end of the rock lever to therebyimpart sudden rockingmovement to the lever in a direction effectivelyoperating the plunger.

In testimony whereof, I have hereunto subscribed my name this 17th dayof J uly,

EMlWA F. AWOOLSON, Ewemtm'm of the Estate of Lionel M. Woolson,Deceased.

